Implement hashlib.new('sha256') and enable it for CLUE

ports/nordic/mpconfigport.mk

@@ -63,6 +63,8 @@ CIRCUITPY_MEMORYMAP ?= 1
 CIRCUITPY_RGBMATRIX ?= 1
 CIRCUITPY_FRAMEBUFFERIO ?= 1
 
+CIRCUITPY_HASHLIB ?= 1
+
 CIRCUITPY_COUNTIO ?= 1
 CIRCUITPY_WATCHDOG ?= 1
 

shared-bindings/hashlib/__init__.c

@@ -20,7 +20,7 @@
 //|
 //| def new(name: str, data: bytes = b"") -> hashlib.Hash:
 //|     """Returns a Hash object setup for the named algorithm. Raises ValueError when the named
-//|        algorithm is unsupported.
+//|     algorithm is unsupported. Supported algorithms for ``name`` are ``'sha1`` and ``'sha256'``.
 //|
 //|     :return: a hash object for the given algorithm
 //|     :rtype: hashlib.Hash"""

shared-module/hashlib/Hash.c

@@ -13,6 +13,9 @@ void common_hal_hashlib_hash_update(hashlib_hash_obj_t *self, const uint8_t *dat
     if (self->hash_type == MBEDTLS_SSL_HASH_SHA1) {
         mbedtls_sha1_update_ret(&self->sha1, data, datalen);
         return;
+    } else if (self->hash_type == MBEDTLS_SSL_HASH_SHA256) {
+        mbedtls_sha256_update_ret(&self->sha256, data, datalen);
+        return;
     }
 }
 
@@ -27,12 +30,19 @@ void common_hal_hashlib_hash_digest(hashlib_hash_obj_t *self, uint8_t *data, siz
         mbedtls_sha1_clone(&copy, &self->sha1);
         mbedtls_sha1_finish_ret(&self->sha1, data);
         mbedtls_sha1_clone(&self->sha1, &copy);
+    } else if (self->hash_type == MBEDTLS_SSL_HASH_SHA256) {
+        mbedtls_sha256_context copy;
+        mbedtls_sha256_clone(&copy, &self->sha256);
+        mbedtls_sha256_finish_ret(&self->sha256, data);
+        mbedtls_sha256_clone(&self->sha256, &copy);
     }
 }
 
 size_t common_hal_hashlib_hash_get_digest_size(hashlib_hash_obj_t *self) {
     if (self->hash_type == MBEDTLS_SSL_HASH_SHA1) {
         return 20;
+    } else if (self->hash_type == MBEDTLS_SSL_HASH_SHA256) {
+        return 32;
     }
     return 0;
 }

shared-module/hashlib/Hash.h

@@ -7,11 +7,13 @@
 #pragma once
 
 #include "mbedtls/sha1.h"
+#include "mbedtls/sha256.h"
 
 typedef struct {
     mp_obj_base_t base;
     union {
         mbedtls_sha1_context sha1;
+        mbedtls_sha256_context sha256;
     };
     // Of MBEDTLS_SSL_HASH_*
     uint8_t hash_type;

shared-module/hashlib/__init__.c

@@ -16,6 +16,11 @@ bool common_hal_hashlib_new(hashlib_hash_obj_t *self, const char *algorithm) {
         mbedtls_sha1_init(&self->sha1);
         mbedtls_sha1_starts_ret(&self->sha1);
         return true;
+    } else if (strcmp(algorithm, "sha256") == 0) {
+        self->hash_type = MBEDTLS_SSL_HASH_SHA256;
+        mbedtls_sha256_init(&self->sha256);
+        mbedtls_sha256_starts_ret(&self->sha256, 0);
+        return true;
     }
     return false;
 }

shared-module/hashlib/__init__.h

@@ -13,4 +13,9 @@
 #define mbedtls_sha1_starts_ret mbedtls_sha1_starts
 #define mbedtls_sha1_update_ret mbedtls_sha1_update
 #define mbedtls_sha1_finish_ret mbedtls_sha1_finish
+
+#define mbedtls_sha256_starts_ret mbedtls_sha256_starts
+#define mbedtls_sha256_update_ret mbedtls_sha256_update
+#define mbedtls_sha256_finish_ret mbedtls_sha256_finish
+
 #endif